This invention relates to aerial toys or novel flying devices, and more specifically to tethered kites with rotary air foils.
It is known in the art to have tethered airborne toys such as kites and devices with rotary air foils. For example, Brumfield, U.S. Pat. No. 2,793,829, describes a rotary kite with a plurality of air foil blades capable of maintaining it airborne with a stabilizing counterbalance functioning in the manner of a traditional kite tail. Similarly, Bilardi, U.S. Pat. No. 4,154,017 describes a tethered body with a single wing rotating on the body; a body rudder controlled by the tethers provides maneuverability and stability. These and other previous disclosures do not provide for flapping on the wing mount the fuselage or a stabilizing air foil keel on the main body.
It is known in helicopter flight that forces on the rotating air foils, or blades, change during a blade revolution due to differences in lift forces as the blade presents a different relative air speed and foil shape to prevailing air movement (wind). If the blade is mounted on a horizontal hinge, set usually at 90 degrees to the span of the blade, it is allowed to oscillate vertically, or flap. The degree of flapping is the result of the cyclical change of balance between centrifugal, inertial, and lift forces. Flapping capability in the hinge mount is provided to provide fuselage stability and relieve stress on the blade mount as opposing blades in different phases of rotation provide unbalanced lift forces.
It is well-known in kite flying that a bias is required in the kite body or the kite becomes unstable. This bias is generally provided in the form of a tail secured to the kite bottom, causing the kite to remain in a preferred orientation. An rudder extended from the kite body or a fuselage has also been found useful in providing this orientation stability, similar to the function of a helicopter tail rotor or a weather vane. As a keel of a boat in water, a keel is provided in this invention on the main body (fuselage), functioning as an improved stabilizer and eliminating the need for a long tail. As in the manner of all keels in fluids, by design the keel opposes movement away from the direction of prevailing wind, yet provides for a quick manuevering response. The position of the keel on the main body helps determine the degree of stability, with a lower position providing increased stability. Adjustment of the keel position allows the operator to adapt the flying device to different flying conditions.
It is therefore an object of the invention to provide an aerial flying device with one or more rotary air foils providing lift to the device in combination with a stabilizing keel on the main body.
It is also an object of the invention to provide tiller means for attaching a tether to the flying device for flight control.
It is a further object to provide an air foil of opposing rotating wings or blades.
It is another object that the opposing blades be mounted on horizontal hinges that allow flapping of the blades.
It is yet another object to provide a means to adjust the position of the keel on the main body of the flying device.
Still another object is to provide for automatic adjustment of the keel position for variable flying conditions.
A final object is to provide a device that can fly in very slight winds.